Birth of U.S. Naval Aeronautics and the
Navy’s Aerodynamics Laboratory
David J. Haas
Eric J. Silberg
Naval Surface Warfare Center, Carderock Division
Sea-Based Aviation and Aeromechanics Branch, Code 532
Presented at the AIAA Centennial of Naval Aviation Forum
21 – 22 September 2011, Virginia Beach, Virginia
AIAA 2011-6943
Copyright © 2011 by David Haas and Eric Silberg. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission.
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American Institute of Aeronautics and Astronautics
Birth of U.S. Naval Aeronautics and the Navy’s
Aerodynamics Laboratory
David J. Haas* and Eric J. Silberg
†
Naval Surface Warfare Center, Carderock Division, West Bethesda, Maryland, 20817
This paper describes the formation of the Navy’s Aerodynamics Laboratory and
its pioneering contributions in naval aeronautics from 1911 to 1919. The Navy was
just beginning serious interest in aviation in 1911 with the procurement of its first
aircraft, the Curtiss A-1. This aircraft was technologically similar to the Wright
brothers’ first airplane but with greater power to allow takeoff from the water using
its large central float. At this time there were no universities that offered degrees, or
even courses, in aeronautical engineering nor were there any government
aeronautics laboratories in the United States. The practice of aeronautical
engineering was largely a process of trial and error. While this method was
successful for small aircraft like the A-1, it posed a significant impediment for
development of larger more capable aircraft. Under the leadership of Rear Admiral
David W. Taylor, the Navy’s “Experimental Wind Tunnel” was designed and built
at the Washington Navy Yard next to the Navy’s Experimental Model Basin to
advance the state of aeronautical engineering. The Navy’s new wind tunnel was the
world’s largest and the centerpiece of the Navy’s Aerodynamics Laboratory. The
laboratory, and the naval constructors who worked there under Taylor, developed
and refined methods for testing scaled models of complete aircraft as well as aircraft
components. These experiments provided the data needed to effectively design large
aircraft and led to the success of the Navy’s NC flying boat. In 1919, an NC was the
first airplane to fly across the Atlantic, just eight years after the Navy procured its
first airplane. This was an accomplishment that at the time was as amazing to the
average person as landing on the moon would be fifty years later. In a decade when
U.S. advancements in aeronautics were waning, the pioneering work of the Navy’s
Aerodynamics Laboratory propelled the Navy to the forefront of aeronautics in the
second decade of the 20th
century. The laboratory established a foundation for the
continued development of aeronautics and left a legacy that continues 100 years
later.
I. Introduction
he U.S. Navy’s early interest in Aviation was sparked by the 1896 success of Professor Samuel
Langley’s unmanned steam powered “aerodrome.” Upon learning of the successful flights of the
aerodrome, then Assistant Secretary of the Navy Theodore Roosevelt saw the potential applications for
naval warfare. In 1898 Roosevelt established a board with Army and Navy representatives to make
recommendations with regard to the practicality of a full sized manned flying machine and supporting
continued experimentation and development by Professor Langley.1 Despite the board’s favorable
recommendations, it would be another ten years before the Navy would seriously consider the potential of
the airplane for naval warfare. In the intervening years the Wrights would capture the world’s attention by
being the first to demonstrate controlled powered flight. However, this achievement started to dim by the
end of the first decade of the 20th
century as European advances in aeronautics took place.
* Aerospace Engineer, Sea-Based Aviation and Aeromechanics Branch, 9500 MacArthur Blvd, Code 532,
West Bethesda, MD 20817, Associate Fellow, AIAA. † Aerospace Engineer, Sea-Based Aviation and Aeromechanics Branch, 9500 MacArthur Blvd, Code 532,
West Bethesda, MD 20817, Senior Member, AIAA.
T
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American Institute of Aeronautics and Astronautics
In September of 1908 the Wrights
demonstrated their flying machine to Army and
Navy observers at Fort Myer, Virginia, across the
Potomac River from Washington, D.C. The Navy
observers present were Lieutenants William
McEntee and George Sweet. Although the
demonstration turned tragic due to an accident that
killed Army Lt. Thomas Sulfridge, a passenger,
the Navy’s interest in aviation was re-ignited.
Flight demonstrations continued in 1910 and 1911
with the first take-off and landing both from a ship
and from the water. The Navy embarked on a
future with aviation in May of 1911 when the first
order for two aircraft from the Curtiss Aircraft
Company was placed, thus marking the birth of naval aviation.2 Although French aviator Henri Fabre was
the first to fly from the water, the Navy’s A-1 “hydroplane” of 1911 developed by Glenn Curtiss was the
first truly successful seaplane (Fig. 1). From this humble starting point in 1911, the Navy would capture the
world’s attention by the end of the second decade of the 20th
century and become the foremost developer of
large flying boats.
To support the scientific development of naval aeronautics, the Navy turned to the Experimental
Model Basin (EMB) at the Washington Navy Yard. The EMB was established in 1898 by then CDR
Taylor3,4
for conducting scientific experiments related to ship hydrodynamics and naval architecture. It
operated under the auspices of the Navy’s Bureau of Construction and Repair and was a world class
experimental facility that helped establish the Navy’s expertise in hydro- and fluid dynamics. LT McEntee,
who earlier observed the Wrights’ demonstration at Fort Myer, worked at the EMB and was an aviation
enthusiast as was his supervisor, then CAPT Taylor, who was in charge of the EMB. Taylor and his staff
began initial investigations of naval aircraft in 1911 using the EMB facilities for hydrodynamic
experiments of seaplane floats and flying boat hulls, as well as for aerodynamic investigations.5
David Taylor was a distinguished naval architect and widely respected researcher with extensive
experience in hydrodynamic testing of ships. Just as he had done for naval architecture earlier, Taylor
recognized the need for scientific facilities to advance the field of aeronautics and he went on to develop
the world’s largest wind tunnel. By 1914 the Navy had the two key facilities critical to becoming the
world’s leader in the design of large flying boats; the Experimental Model Basin to measure hydrodynamic
forces on the hull and the Experimental Wind Tunnel (EWT) to measure aerodynamic forces on the
aircraft. With these facilities, aircraft design could advance from an art of trial and error based on
experience (as was the case in 1911) to the engineering science of aeronautics (as would be needed for the
design of the NC flying boat). Using these experimental facilities over the course of just a few short years,
the Navy would design and build a flying boat larger than any before that would be the first to fly across
the Atlantic.6,7
The pioneering work of David Taylor and his colleagues at the Navy’s Aerodynamics
Laboratory propelled the Navy to the forefront of aeronautics by 1919. It would not be until the early
1920’s when the National Advisory Committee for Aeronautics (NACA) began operations of their first
wind tunnel before another laboratory in the United States would rival that of the Navy’s.
The focus of this paper is on the early years of the Navy’s Aerodynamics Laboratory from 1911 to
1919. This period is significant because aeronautics in the Navy came of age at a time when there were no
aeronautical engineering curricula taught at any university in the United States. In addition, very rapid
progress in naval seaplane development took place between 1911 and 1919, starting from the 1500 pound
A-1 hydroplane procured in May 1911 and culminating with the 28,000 pound NC flying boat that crossed
the Atlantic Ocean in May of 1919. The development of the NC flying boat was no small feat; a large
flying boat is far more complex to design than a land based aircraft, as it must perform the functions of two
vehicles in one, a fully sea worthy boat capable of surviving rough seas and an aircraft capable of long
missions with significant payloads.
In preparing this paper, the authors, who are aerospace engineers at the Navy’s David Taylor Model
Basin located at the Carderock Division of the Naval Surface Warfare Center, reviewed over 150 original
wind tunnel reports from the Navy’s Aerodynamics Laboratory and inspected many of the actual models
that were tested. RADM Taylor’s personal collection of papers and memorandums were also examined, as
well as early photographs involving tests at the Navy’s Aerodynamics Laboratory.
Figure 1. The Navy’s first airplane, the Curtiss
Model A-1.
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American Institute of Aeronautics and Astronautics
The development of naval aeronautics from 1911 through 1919 is presented in three parts. The first part
spans from 1911 to 1913 when the Navy procured its first aircraft and established the foundations of the
Navy’s “Aerodynamical” Laboratory, as it was originally referred. During this time, the Navy utilized the
Experimental Model Basin to evaluate seaplane floats and measure forces on airplane wings. The second
part focuses on the period from 1914 to 1916 when the Navy opened its Experimental Wind Tunnel and
utilized it to develop the first Navy designed aircraft. The third part spans from 1917 to 1919 and describes
the Aerodynamics Laboratory’s support for the war effort and the development of the NC flying boat,
including a comprehensive review of the many types of tests conducted in the Navy’s Experimental Wind
Tunnel.
II. 1911-1913: Navy Procures its First Airplane and Establishes the Foundation for an
“Aerodynamical Laboratory”
To be truly useful to the Navy, aircraft needed to be capable of operating from the sea. This requirement
added significant technical challenges to the design. In addition to determining lift and drag of the wings
and control surfaces, knowledge of the hydrodynamic lift and drag of the hull or floats at high speed was
needed. Despite previous failed attempts in 1908 to design a seaplane, Glenn Curtiss once again
concentrated his efforts on development of a “hydro-aeroplane” in 1910.8 His earlier attempts were
unsuccessful due largely to a combination of power limitations of engines of that time and the high drag
and suction forces of early seaplane floats. In 1911, Glenn Curtiss delivered the first successful hydro-
aeroplane (or hydroplane) to the Navy. This aircraft was designated the Model A-1. Later that year the first
Naval Air Station was established at Annapolis, Maryland for aircraft experimentation and flight training.
In 1912, Curtiss redesigned the center float of his seaplane into a strengthened and enlarged hull and
delivered the first successful flying boat to the Navy designated Model AB-1. The flying boat concept
would prove to be so useful to naval aviation that it would provide utility in naval operations for half a
century.
In 1911, under the direction of then CAPT Taylor, the EMB at the Washington Navy Yard was well
established as a preeminent scientific test facility for the study of hydrodynamic forces on ships. With the
delivery and evaluation of the A-1 hydroplane, Taylor realized that the Navy would need an equivalent
facility for the study of aerodynamic forces on aircraft. Taylor obtained authorization to begin aeronautical
investigations at the EMB and initiated efforts to design and build the Experimental Wind Tunnel to serve
the same purpose for aircraft as his EMB did for ships starting some thirteen years earlier. To improve the
poor hydrodynamic performance of early seaplane floats, Taylor utilized the expertise and facilities at the
EMB.5 A systematic set of float tests were initiated at the EMB in 1911 and continued into 1912. Various
types of float configurations were investigated, including wing section floats, sled-type box floats, canoe
shaped floats, as well as single and twin floats with various step configurations and V-bottoms. These basin
tests were of great value, providing data on hull resistance at different trim points, planing capacity,
righting moments at rest, tendency of porpoising, and spray patterns.9 During this time frame, tests to
measure lift and drag on wings was also undertaken in the EMB. Review of early logs of EMB models
show that tests were conducted on pontoon floats for the Wright, Curtiss, and Burgess-Wright seaplanes, as
well as many others. In 1913, numerous tests of flying boat hulls were conducted, including designs from
Curtiss and Burgess. Indeed, the EMB proved to be an invaluable tool in the development of the Navy’s
seaplanes and flying boats.
Figure 2 shows a model of the Curtiss A-1 and an early Model-F type flying boat undergoing tests at the
EMB. The basin tests were conducted by LT William McEntee, later joined by LT Holden Richardson,
both of whom were naval constructors and assistants to David Taylor. These experiments helped to
quantify the benefits of adding a step in the float to reduce the speed where the hull planes on the water at
reduced drag, thereby increasing takeoff performance of early seaplanes significantly. A critical challenge
in the design of seaplanes is to determine the proper relationship between the planning surface of the hull
and the angle of incidence of the wings to ensure a smooth transition from hydrodynamic lift produced by
the hull and aerodynamic lift produced by the wings. A successful configuration will provide sufficient
speed at takeoff to ensure adequate aerodynamic control and efficient cruise in the air within the power
limitations of the engine.
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American Institute of Aeronautics and Astronautics
Along with testing seaplane floats and hulls in 1912, Richardson studied the pioneering wind tunnel
research of French architect Gustave Eiffel from Eiffel’s 1911 book, The Resistance of the Air and
Aviation, and he, Taylor, and McEntee began design of a suitable wind tunnel facility for the Navy’s work
in aeronautics and aircraft development.10
In 1913, funds were appropriated for the construction of what
would be the world’s largest wind tunnel. Construction of the tunnel and a building to house it began at the
Washington Navy Yard that same year (Fig. 3). At this period in time, the use of large wind tunnels to
evaluate complete aircraft designs was virtually
nonexistent. Realizing the importance of developing
aeronautics as a field of study, the Navy sent Lieutenant
Jerome Hunsaker to MIT for graduate studies, to develop a
course in aeronautics (the first in the country), and to design
experiments for aircraft. Hunsaker built a wind tunnel at
MIT for experimentation with a 4-foot square test section
similar to that used at the National Physical Laboratory in
England. Hunsaker completed his PhD at MIT in 1916 and
returned as a naval constructor to play an important role in
the design of the NC flying boat. The summer of 1913
brought both accomplishment and tragedy; an attitude
record of 6200 feet was established in a Model A-2 and the
first naval aviation fatality occurred on June 20.
III. 1914-1916: Navy Opens World’s Largest
Wind Tunnel and Designs First Seaplane
In 1914 the first training facility for naval aviators was
established in Pensacola, Florida. In the same year, the
wind tunnel at the Washington Navy Yard was completed
and the Navy’s Aerodynamics Laboratory officially
opened. Also, in 1914 David Taylor was promoted to rear
admiral and appointed Chief Constructor of the Navy in
charge of the Bureau of Construction and Repair. The
Experimental Model Basin and the Aerodynamics
Laboratory were both under this bureau. Taylor appointed
CDR McEntee director of the newly established
Aerodynamics Laboratory. The Experimental Wind Tunnel
at the Laboratory featured a closed circuit design with a test
section (or experimental chamber as it was called then)
measuring 8-feet by 8-feet, the largest in the world (Figs. 4,
5). It was constructed entirely of wood with frames spaced
about three feet apart on the outside of the circuit and
sheathed on the inside with 7/8th
inch tongued-and-grooved
sheathing. The fan blower was a paddle type with a top-
Figure 2. Test of Curtiss A-1 (left) and Model F (right) in the Experimental Model Basin.
Figure 3. Navy’s 8-foot by 8-foot Wind
Tunnel under construction at the
Washington Navy Yard (top), and the
completed Aerodynamics Laboratory
building (bottom).
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horizontal discharge duct measuring 7.5 feet by 9 feet and
an inlet diameter of 11 feet 2 inches. It was powered by a
250 volt, 500 horsepower direct drive motor.11
The tunnel was run for the first time in March 1914 and
underwent a period of calibration in the latter part of the
year. For validation of the new tunnel, measurements were
compared to those obtained from tests conducted in the
smaller wind tunnel at MIT and with experiments
conducted in the wind tunnel at the National Physical
Laboratory in England. Tests of wings used in Eiffel’s
experiments were also conducted as a preliminary check of
tunnel accuracy.12
A honeycomb grid of 64 one-foot square
ducts eight feet long (in the direction of flow) was installed
ahead of the test section and three intermediate vertical
“splitters” were installed in the return10,11
(Fig. 6). These
ducts and splitters could be adjusted to enhance flow
quality. Each cell of the honeycomb grid had a damper in
order to control the velocity of air such that at the position
of the model in the test section the maximum variation from
the uniform flow was about two percent.11
Normal test
speed was forty miles per hour, with a maximum of seventy
five. At the discharge side of the fan were located twelve
pitot tubes which led to an integrating manometer
measuring the average discharge velocity. This velocity was
calibrated against the velocity in the test section and used as
a means of setting the test speed without introducing pitot
tubes into the test section. The pitot tubes were checked
with those used at the aerodynamics laboratory at MIT and
at the National Physical Laboratory. A series of vent holes
was located in the tunnel walls just down stream of the test
section. These holes served the dual purpose of introducing
fresh cool air and maintaining the gradient of pressure in
the test section.
To measure force and moment data, the model was
mounted on a steel spindle extending through the top of the
tunnel to an Eiffel type balance that measured lift, drag (or
“drift” as it was called), and pitching moment. In addition
to the Eiffel balance, a special torsion balance was designed
to provide a more accurate measurement of pitching
moments. By changing the orientation of the model, the
Figure 4. Scaled model (top) and
Schematic (bottom) of Navy’s first wind
tunnel.
Figure 5. Technician in Experimental
Wind Tunnel
Figure 6. Vertical splitters (left) and 8-foot by 8-foot grid (right) were used to adjust the
flow field.
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torsion balance could measure yaw or roll
moments. Because of the large size of the test
section, complete aircraft models with a wing span
of three feet or more could be tested. At the typical
test speed of 40 miles per hour, drag forces as low
as 1/10 of a pound needed to be measured
accurately requiring a balance accuracy of 2/1000
of a pound.11
A bifilar wind balance, where the
model is attached by thin steel wires, was also
utilized to test airship hulls, struts, and airfoils
providing uniform and consistent measurements of
resistance. Later, in June of 1920, a full six-
component balance designed and built by the
laboratory was installed. This balance allowed the
collection of all six forces and moments on the
model at once and reduced the time to collect data
for a typical sweep of sixteen model incidence
settings at a given airspeed from eight hours to less
and half an hour. These balances were installed
directly above the test section in the observation and control room (Fig. 7).
Numerous tests were conducted in the early years of operation. Complete airplane models were tested,
including designs that were already in use and others still under development. Other investigations
conducted in the wind tunnel during this period include determining the coefficient of air friction for
various airplane and balloon fabrics, aerodynamic forces on a dirigible building, as well as tests for a
number of private concerns.11
The large size of the tunnel even made it possible to test full-sized radiators
for airplane motors both for air resistance and cooling capacity in a comparative manner. Non-aeronautical
tests were also conducted. In fact, the first test in the tunnel examined the effect of varying dimensions of
ships’ ventilation cowling.11,12
These tests indicated that many of the contemporary designs were larger
than necessary, taking up valuable space in the confines of a ship.
By 1916, standard wind tunnel tests had been developed to analyze the lift, drag, performance, and
stability of complete aircraft. Data collected during these tests were compiled in the form of plots of lift,
drag, and lift-to-drag ratio versus angle of attack. The maximum and minimum speeds were also estimated
from the measured drag using an assumed engine power and propeller efficiency. In addition, a series of
resultant force vectors corresponding to each angle of attack measured was presented on a schematic of the
airplane model (Fig. 8). This early data presentation method provided the means to quickly assess the
aerodynamic performance, trim, control effectiveness, and longitudinal stability characteristics of the
aircraft configuration under study. The slope of a vector relative to the free stream velocity indicates the
lift-to-drag ratio, the location of a vector relative to the aircraft center of gravity indicates the trim state, and
the movement of the vectors as the angle of attack changes indicates if the aircraft is statically stable.
Longitudinal control
effectiveness could be assessed
by observing how far the vectors
moved fore or aft with different
angles of elevator incidence.
Although a compete account
of models tested before 1917 in
the EWT is not available, it is
estimated that 100 models were
tested in the wind tunnel from
mid-1914 through 1916 based on
existing documentation of wind
tunnel model numbers. Several
wind tunnel models of the
Sturtevant S-4 seaplane trainer
(Fig. 8) were tested in late 1916
and early 1917. Initially a small
Figure 7. Wind tunnel observation and control
room.
Figure 8. Force vectors displayed on schematic of Sturtevant S-4
model as tested in 1916.
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S-4 model was tested in the 4-foot tunnel at MIT at
30 miles per hour. This model was then tested in
the 8-foot tunnel at the Washington Navy Yard for
comparison (but at 40 and 50 miles per hour and
extrapolated to 30 miles per hour). In December, a
36 inch wingspan “double size” model of the same
vehicle was also tested in the EWT to compare
with the same ratio of model-size to tunnel-size.‡
This model was labeled wind tunnel model
number 114. Models tested in the Washington
Navy Yard in 1917 began with wind tunnel model
number 115 and increased thereafter.
With war in Europe underway and realizing the
limited performance and quality of seaplanes
available from airplane manufacturers in 1914, the
Navy initiated design of its own seaplane at the
Aerodynamics Laboratory under Richardson’s
lead. The aircraft, designated the 82-A, was the
first aircraft designed and built entirely by the
Navy, or any U.S. government agency. It was a
large aircraft for its time. Weighing 6000 pounds
and with three seats, it was also one of the earliest
twin-engine seaplanes. In the summer of 1915,
Richardson conducted tests of the 82-A float
system, which included a large center float and
smaller wing floats, in the EMB. In December of that year, he evaluated the performance of the design in
the EWT (Fig. 9). The aircraft was built at the Washington Navy Yard and underwent flight testing on the
Anacostia River in 1916 with Richardson (who was designated Naval Aviator No. 13 and was the Navy’s
first engineering test pilot) in charge (Fig. 10). Although the 82-A, which was also known as the
Richardson Seaplane, never went into production, it signified the coming of age of the Navy’s
Aerodynamics Laboratory. The Navy’s new wind tunnel was described to the general public in a 1917
article in Popular Science with the title, “Testing Airplanes in a Man-Made Storm” and showed a model of
the 82-A as well as a ship model in the wind tunnel.
‡ The Aeronautical Report for this test notes that the lift to drag ratio was higher for the larger model tested
at higher airspeed in the EWT. These results are consistent with what would be expected based on
Reynolds number scaling effects, although model scale effects were not fully understood in 1916.
Figure 9. First Navy designed aircraft, the 82-A,
in the wind tunnel at the EMB (1915).
Figure 10. The 82-A undergoing testing on the Anacostia River and at the Washington Navy
Yard.
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IV. 1917-1919: Naval Aeronautics Matures, Leads to First Flight Across Atlantic
On April 11, 1917, when the United States entered World War I, the Navy’s inventory of aircraft
included forty-five seaplanes, six flying boats, and one airship. The need for developing and fielding
capable seaplanes was more urgent than ever. By this time the pace of testing at the Aerodynamics
Laboratory was substantial and the wind tunnel was operating 16 hours per day. Chief Constructor Taylor
hired Dr. Albert F. Zahm to direct the Laboratory in January of 1917. Zahm was a long-time acquaintance
of Taylor and in his scholarly work, even expressed his indebtedness to Taylor for suggesting the topic of
his 1903 research on the measurement of air velocity and pressure.13
Dr. Zahm was a well known pioneer in
the field of aeronautics by this time and no stranger to the wind tunnel. In 1901, as a professor of
mechanics at Catholic University, Dr. Zahm built an aerodynamics laboratory with a wind tunnel that had a
large 6-foot square test section. This tunnel remained in operation until 1908. Later, working for Glenn
Curtiss, he designed seaplanes as well as the wind tunnel balance for the their 4-foot by 4-foot wind tunnel
and advanced to the position of Chief Research Engineer for the Curtiss Airplane Company.
A methodical researcher and true aeronautical engineer, Dr. Zahm instituted a discipline of formally
documenting wind tunnel test setups and data collected in Aeronautical Reports issued by the Laboratory.
One hundred forty nine Aeronautical Reports were written between 1917 and 1919 describing many types
of tests and documenting the data collected. Once in charge of the Laboratory, Dr. Zahm wasted no time
getting to work and the first three Aeronautical Reports were issued in January 1917. The second of these
reports described a wind tunnel test on the “Resistance and Controllability of School Dirigibles” which
included a photograph of the airship model (Fig. 11) identifying it as wind tunnel model number 115. This
model corresponds to an airship designed by LT Hunsaker that became the Navy’s first successful airship,
the B-class blimp. The Navy procured sixteen B-class blimps for patrol service along the coast. The airship
had a displacement of 77,000 ft3, a speed of 45 miles per hour, and a payload of 2000 pounds.
Due to the large size and flexible nature of the tunnel design, many types of tests were conducted
between 1917 and 1919. In addition to models of complete seaplanes and airships, aerofoils (as they were
called at that time), control surfaces, aircraft fuselages, airship cars, and seaplane hulls and floats were
evaluated as well as miscellaneous models including bombs, parachutes, aircraft and wind tunnel
instruments, wind driven accessories, cables and struts, and even ships. Table 1 summarizes testing in the
Aerodynamics Laboratory for this three year period as well as for each individual year to provide insight
into the types and numbers of tests that were important to the Navy at that time. Approximately fifty
Aeronautical Reports were written each year. Although the vast majority of these reports correspond
directly to wind tunnel tests, some were devoted to
descriptions of wind tunnel instruments, analytical
methods of data reduction, or hydrostatic tests of
airship models filled with water.
As seen in Table 1, the most frequently
occurring tests were of complete aircraft. In early
1917, numerous speed scouts, trainers, and other
small seaplanes were tested including the Curtiss
N-9, one of the most popular trainers in World
War 1 (Fig. 12). Large flying boats with long
range and high endurance were of great interest to
the Navy to patrol the waters off the coast of
Europe for U-boats without the need for a ship
tender. In 1918, various configurations of large
flying boats, including the initial design of the
Figure 11. The first aircraft model tested in 1917
was this B-class blimp model, the Navy’s first
successful airship of which 16 were built for
coastal patrol.
Figure 12. Numerous tests of small seaplanes including these speed scouts and trainers took place in
early 1917.
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famous NC flying boat, were evaluated. Figure 13 shows a wind tunnel model of a “1000 hp seaplane”, an
early configuration of the NC flying boat, that was tested in November of 1917. This designed evolved into
the NC-1 configuration after modifications guided by both wind tunnel and model basin tests. The NC-1
configuration was tested in the wind tunnel in January of 1918 (Fig. 14). The hull of the NC flying boat
with several stern variations was also tested in the wind tunnel in March of 1918 and in the model basin to
optimize its shape for both hydrodynamic and aerodynamic efficiency. The NC-1 configuration (with
observer station located on top of the upper wing as shown in Fig. 14) was first flown on October 4, 1918.
During 1918 and 1919, flying boats even larger than the NCs were tested. Figure 15 shows two giant
60,000 pound flying boats that were tested in the latter part of 1918. Other significant flying boats that were
tested in the wind tunnel include models of the HS-1 (6,000 lb class) and H-12 (10,000 lb class) in 1917
and the F-5-L (13,000 lb class) in 1919 (Figs. 16, 17). The model of the F-5-L was one of the largest
airplane models tested, with a wing span of fifty two inches. The capabilities of the flying boat were so
significant to naval aviation that by November of 1918 there were over 1,100 in the navy inventory. The
year 1917 saw the greatest number of airplane designs tested. Review of the individual test reports indicates
that in the earlier part of 1917 most tests were of smaller aircraft types whereas the latter part of the year
involved testing of larger flying boats. This coincides with a 1917 directive issued by RADM Taylor to
develop a self deployable aircraft to combat the German U-boat menace. He assigned Hunsaker and
Richardson the task of making the concept a reality. To accomplish Taylor’s vision, the Navy worked with
Glenn Curtiss to design, build, and ultimately fly the first aircraft across the Atlantic, the NC-4 flying boat.
Table 1. Summary of wind tunnel tests conducted at the Navy’s Aeronautical Laboratory from
1917 through 1919.
Aeronautical Reports and Type of Test 1917 1918 1919 Total
Aerodynamics Laboratory Reports 54 46 49 149
Wind Tunnel Tests Conducted 48 41 46 135
Complete Airplanes 22 11 6 39
Airships (Blimps, Dirigibles) 3 3 12 18
Aerofoils 6 4 3 13
Control Surfaces 2 1 2 5
Isolated Fuselage, Float/Hull, Airship Carriage 4 4 3 11
Aircraft Radiators 1 5 1 7
Wind Driven Devices and Air Screws 1 5 0 6
Instrumentation Tests and Calibrations 7 7 9 23
Bombs 1 0 1 2
Ship Airwakes 0 0 1 1
Ship Wind Deflector and Ventilators 1 0 2 3
Parachutes 0 0 1 1
Aircraft Cables and Struts 0 1 5 6
Figure 13. The design concept that later became
the NC flying boat was first tested in November
of 1917.
Figure 14. An early configuration of the NC-1
as well as several hull forms were tested in early
1918.
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Figure 18 shows a 1918 model of a rigid airship
designed and tested by the Aerodynamics
Laboratory. In late 1918, the Navy requested
funding for four large Zeppelin-type rigid airships.
Table 1 shows that testing of airships was somewhat
modest in 1917 and 1918, but consumed a
significant amount of test time in 1919. In 1919,
twelve separate tests of airship models were
conducted and two additional tests were conducted
on various airship “cars” (Fig. 19). Despite the
emphasis of testing complete aircraft models to
Figure 15. Tests of giant 60,000 pound flying boats took place beginning in the latter part of 1918.
Figure 16. Most of the Navy’s flying boats were
tested in the Navy’s wind tunnel including the
HS-1 (top) and H-12 (bottom) aircraft.
Figure 17. This model of the F-5-L flying boat
was tested in 1919 and was one of the largest
airplane models tested with a wingspan of 52
inches.
Figure 18. Model of rigid airship tested in 1918.
Figure 19. Various cars for airships were also
evaluated in the wind tunnel.
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American Institute of Aeronautics and Astronautics
evaluate overall performance of
a specific design, there were also
a significant number of tests
devoted to basic airfoil
characteristics. Some of these
tests evaluated new airfoils
developed by the Navy against
the existing RAF-6 airfoil, a
standard airfoil of the time. In
addition to standardized tests of
complete aircraft, standardized
tests and model sizes were
established for airfoils to
measure lift, drag, and the center
of pressure. In a 1917 test of
various airfoils, a twenty-hole
manometer was utilized to
measure the pressure distribution
on the upper and lower surfaces
of the airfoil. Comparison of test
results with those obtained from
other smaller wind tunnel
facilities was conducted to gain
insight into the effects of model
and test section size. Airfoils
were tested in two standard
sizes, 30 inches by 5 inches and
48 inches by 8 inches, the
smaller size also having been
tested in smaller 4-foot wind
tunnels. Figure 20 shows an
airfoil-like model of a control
surface as tested in the wind
tunnel and a photograph of the
“aerofoil cabinet” in the
Aerodynamics Laboratory in
1922.
In 1918, to lessen the
demand on the 8-foot by 8-foot
tunnel, the Aerodynamics
Laboratory built a smaller 4-foot
by 4-foot flow-through wind
tunnel similar to those at MIT
and the National Physical
Laboratory. In addition, to
broaden the speed range of the
EWT, a special insert was
designed to reduce the size of the test section to 8-feet by 4-feet, thereby increasing the maximum test
speed to 120 miles per hour. Also in 1918, the Aerodynamics Laboratory tested a model of the N-1. The N-
1 seaplane was the Navy’s first attack aircraft and included a large Davis Gun mounted at the nose (Fig.
21). This aircraft was designed and built entirely by the Navy and was one of the first airplanes built at
Philadelphia’s newly established Naval Aircraft Factory in 1918.
Full-sized aircraft components continued to be tested. Figure 22 shows a functioning aircraft radiator,
along with part of the aircraft fuselage, installed in the EWT. This was tested for its cooling capability as
well as its aerodynamic characteristics. Air driven systems such as the fuel pumps on the F-5-L were tested
in 1918 (Fig. 23). A number of unique looking and unusual airplane configurations were tested in the wind
Figure 20. Control surfaces (left) and airfoils were tested in the
wind tunnel from 1917 to 1919, a number of which can be seen in
the “aerofoil cabinet” (right).
Figure 21. A model of the N-1 was tested in 1917; this seaplane
was Navy’s first attack aircraft.
Figure 22. Full-sized functioning
aircraft radiators were evaluated in
the wind tunnel for cooling efficiency
and drag, some included portions of
the fuselage as seen here.
Figure 23. Air driven
systems such as these fuel
pumps on the H-12 flying
boat were tested in the
wind tunnel (1918).
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American Institute of Aeronautics and Astronautics
tunnel or evaluated by the Laboratory staff. Figure 24(a) shows a
futuristic monoplane model that was evaluated in the wind tunnel.
This model had a surprisingly large lift to drag ratio despite its
substantial undercarriage. Figure 24(b) shows a “tandem triplane”
model that was also tested in late 1918. Although rotary wing
aircraft were far behind in development compared with fixed wing
aircraft, two early Aeronautical Reports addressed this topic. One
involved a technical review of a proposed 1918 “hovering
aeroplane” concept. No wind tunnel test was conducted, but the
report concluded, “It is believed that, with present light motors of
great power, a suitably designed aeroplane can be made to rise
vertically from rest, hover stationary in still air, glide safely with
passive motor or settle vertically to earth with active motor.” It was
recommended that “at an opportune time some elementary
experiments be made at the Naval Yard Aeronautical Laboratory, to
furnish a basis for correct design of a hovering airplane”. The report
also concluded that the specific proposed design was, “not
sufficiently developed to be referred onward.” The second report
involved an earlier wind tunnel test conducted in 1917 to measure
drag on a free spinning eight-bladed “passive airscrew,” see Fig. 25.
A number of “airscrews” were tested and the report concluded, “it
appears practical to design a helicopter screw where resistance to fall
shall exceed that of a disc of equal diameter.”
The end of 1919 concluded a significant chapter in naval aviation. The war was over and the value of
naval aviation with airplanes that could operate from the sea was firmly established. The Navy’s
aeronautics capability had been demonstrated vividly with the triumphant flight of the NC-4 across the
Atlantic. As the next decade of the 20th
century began, so did a new chapter in the advancement of
aeronautics as the first wind tunnel of NACA became operational.
V. The Legacy of David W. Taylor – 100 Years of Aeronautics
Although David W. Taylor is remembered most for his role in naval architecture and fluid dynamics, he
left an indelible mark on the development of aeronautics in the United States. Taylor, as well as his
protégés Holden Richardson and Jerome Hunsaker, went on to serve important roles in the formation of and
maturing of NACA. Taylor’s legacy in aeronautics spans 100 years and continues today at the David
Taylor Model Basin at the Naval Surface Warfare Center, Carderock Division. The Experimental Model
Basin and Aeronautics Laboratory were relocated to Carderock, Maryland beginning in 1939 with greatly
improved and expanded facilities. RADM Taylor lived long enough to attend the dedication of the new
model basin at Carderock bearing his name and CAPT Richardson was recalled from retirement during
World War II to manage operations of the new wind tunnels at Carderock.
a) b)
Figure 24. Some of the more unusual aircraft configurations tested include a monoplane (a) and
tandem triplane (b) both tested in late 1918.
Figure 25. Tests of “passive
airscrews of great resistance”
were conducted in 1917 such as
this 8-bladed “helicopter screw”.
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American Institute of Aeronautics and Astronautics
Beginning initially with two 8-foot by 10-foot
subsonic wind tunnels, the facilities at Carderock
continued to expand over the decades to include
transonic, supersonic, and hypersonic wind tunnels
as well as a specially designed acoustic wind
tunnel with a 24-foot square anechoic test
chamber. A wide variety of tests have been
conducted in these facilities including aircraft store
separation studies in the transonic tunnel,
evaluations of advanced aircraft and rotor systems
including circulation control wings and rotors, and
wing-in-ground effect high-speed ships to name a
few. In 1961 a wind tunnel test was conducted in the 8-foot by 10-foot wind tunnel of a model of the
Navy’s first seaplane, the Model A-1 to commemorate the 50th
anniversary of naval aviation (Fig. 26).
Beginning with the first test in David Taylor’s wind tunnel in 1914, the Naval Surface Warfare Center,
Carderock Division has continuously operated wind tunnels longer than any government organization in the
United States (Fig. 27). Today, the Navy’s large subsonic wind tunnel and anechoic flow facility at
Carderock continue to be utilized to support testing of all types of vehicles and systems of interest to the
Navy.
Acknowledgments
The authors would like to thank the museums, historians, and archivists that have assisted with all the
research that went into this paper: Curtis Utz, Roy Grossnick, and the rest of the aviation staff from the
Naval History and Heritage Command; CAPT Robert Rasmussen (ret) director of the National Museum of
Naval Aviation; Dr. Jeremy Kinney, Roger Connor, Dr. John Anderson, and Larry Wilson from the
National Air and Space Museum, and Clistine Johnson and Dana Wegner from Naval Surface Warfare
Center, Carderock Division.
References
1Turnbull, A and Lord, C, History of United States Naval Aviation, Yale University Press, New Haven, CT, 1949. 2Grosnick, R, United States Naval Aviation 1910-1995, Naval Historical Center, Dept. of the Navy, Washington
D.C., 1997. 3Allison, D.K., Keppel, B.G., and Nowicker, C.E., D.W. Taylor, United States Printing Office, Washington D.C.
1986. 4Hovgaard, W., Biographical Memoir of David Watson Taylor 1864-1940, presented to the Academy at the Annual
Meeting, 1941, Published by the National Academy of Sciences, Washington 1941.
Figure 26. A model of the A-1 was tested in the
Navy’s 8-foot by 10-foot subsonic wind tunnel at
Carderock in 1961 commemorating the 50th
anniversary of naval aviation.
Figure 27. The Navy’s large subsonic wind tunnel
at Carderock is used today to evaluate all types of
vehicles and systems of interest to the Navy.
14
American Institute of Aeronautics and Astronautics
5Richardson, Holden. C., “Naval Development of Floats for Aircraft,” Transactions of the Society of Naval
Architects and Marine Engineers, Vol. 34, Nov. 1926, pp. 15-28. 6Haas, D.,Silberg, E., and Milgram, J. “Birth of U.S. Naval Aeronautical Engineering and Phenomenal Rise to
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the First Transatlantic Flight” Technical abstract submitted to the AIAA Centennial of Naval Aviation Forum, 21-22
Sept 2011, Virginia Beach, VA. 8Casey, L., Curtiss: The Hammondsport Era 1907 to 1915, Crown Publishers, New York, NY, 1981. 9Richardson, Holden. C., “The Trend of Flying Boat Development,” Journal of the American Society of Naval
Engineers, Vol. 38, No. 2, May, 1926, pp. 231-253. 10Fresh, J, “The Aerodynamics Laboratory (The First 50 Years),” David Taylor Model Basin Aero Report 1070,
Jan. 1964. 11McEntee, Willian, , “Navy has Largest Experimental Wind Tunnel” Journal of the American Society of Naval
Engineers, Vol. 27, No. 2, pp 603-607, May 1916.
12Richardson, H.C., memorandum dtd. Dec. 10, 1941. H.C. Richardson Collection, Box III. Naval History and
Heritage Command, Washington Navy Yard, Washington, D.C. 13Zahm, A., “Aeronautical Papers: 1885-1945 of Albert F. Zahm,” Paper no. 15, Measurement of Air Velocity and
Pressure (Physical Review, Dec. 1903), pp.113-121, The University of Notre Dame, Notre Dame, IN, 1950.
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